Questions and Answers
What is the difference between prokaryotic chromosomes and eukaryotic chromosomes?
Prokaryotic cells have a single circular chromosome attached to the cell membrane, while eukaryotic cells contain free-floating linear chromosomes within a nucleus.
Before a cell divides, what happens to the cell's chromosomes?
They are duplicated.
What happens to eukaryotic chromosomes with each cell division?
They are shortened.
How do telomeres partially solve the shortening problem?
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What is a telomere?
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Teolmerase is?
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Describe Binary Fission in Prokaryotes.
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Are telomeres used in binary fission in prokaryotes?
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What are the 5 stages of the eukaryotic cell cycle and what occurs at each stage?
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Which of the stages of the eukaryotic cell cycle occur during interphase?
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Why must a cell's DNA be replicated for cell division to occur?
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What enzymes are used in the DNA replication process?
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Explain unwinding and rebuilding as used in the DNA replication process. What is the result?
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Why is DNA replication a semi-conservative process?
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What are the characteristics of cancer?
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What is metastasis?
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What is the difference between normal cells and cancer cells?
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Why are cancers dangerous?
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Study Notes
Chromosomes in Prokaryotes vs. Eukaryotes
- Prokaryotic chromosomes are single and circular, attached to the cell membrane.
- Eukaryotic chromosomes are linear, free-floating, and contained within a nucleus.
Chromosome Duplication Before Division
- Chromosomes are duplicated before cell division to ensure each daughter cell receives identical genetic material.
Eukaryotic Chromosome Shortening
- With each division, eukaryotic chromosomes become shorter, impacting genetic information over time.
Telomeres and the Shortening Problem
- Telomeres shorten with each division, providing a buffer against immediate loss of functional DNA.
- Functional DNA loss occurs after approximately 50 divisions in humans, leading to cellular aging and death.
Definition of Telomeres
- Telomeres are repetitive non-coding DNA sections that protect chromosome ends from degradation.
Role of Telomerase
- Telomerase is an enzyme that extends telomeres, allowing for continued cell division and longevity in some cells.
Binary Fission in Prokaryotes
- DNA is copied exactly, the cell elongates, and eventually splits into two daughter cells.
Telomeres in Binary Fission
- Telomeres are not utilized in binary fission since prokaryotic chromosomes lack them.
Stages of the Eukaryotic Cell Cycle
- Gap 1: Cell undergoes primary growth and normal functions like protein synthesis.
- DNA Synthesis: Each chromosome replicates to prepare for division.
- Gap 2: Further growth and preparation for mitosis.
- Mitosis: Division of the parent cell's nucleus and duplicated chromosomes.
- Cytokinesis: Division of the cytoplasm into two daughter cells, each receiving a complete set of DNA.
Interphase Stages
- Interphase consists of Gap 1, DNA Synthesis, and Gap 2.
Importance of DNA Replication
- DNA replication is essential for providing daughter cells with an identical genetic blueprint.
Enzymes in DNA Replication
- Unwinding and rebuilding enzymes are critical in separating DNA strands and synthesizing new strands.
Unwinding and Rebuilding Process
- DNA unwinds into two strands, and enzymes add nucleotides to form new complementary strands, resulting in two double-stranded molecules identical to the original.
Semi-Conservative DNA Replication
- Each new DNA molecule contains one strand from the original and one newly synthesized strand.
Characteristics of Cancer
- Cancer cells exhibit no contact inhibition and continue to divide uncontrollably.
Metastasis Explained
- Cancer cells lack cohesion, allowing them to spread rapidly throughout the body, forming secondary tumors.
Normal vs. Cancer Cells
- Normal cells stop dividing upon contact with other cells, while cancer cells ignore such signals and continue to proliferate.
Dangers of Cancer
- Malignant tumors can grow large enough to disrupt surrounding tissues and organs, potentially leading to fatal outcomes.
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Description
Test your knowledge of chromosomes and the cell division process with these flashcards. Learn the key differences between prokaryotic and eukaryotic chromosomes, and understand what happens to chromosomes before cell division. Perfect for students studying biology at any level.